Wis. Admin. Code Department of Workforce Development DWD 80.26 - Loss of vision; determination

The following rules for determining loss of visual efficiency shall be applicable to all cases settled after December 1, 1941, irrespective of the date of injury, except that, in the examples for computations of compensation payable and of the percentage of permanent total disability, the computation of the percentage of visual impairment must be applied to the provisions of the worker's compensation act as they existed at the date of the injury.

(1) MAXIMUM AND MINIMUM LIMITS OF THE PRIMARY COORDINATE FACTORS OF VISION. In order to determine the various degrees of visual efficiency, a) normal or maximum, and b) minimum, limits for each coordinate function must be established; i.e., the 100% point and the 0% point.

(a) Maximum limits. The maximum efficiency for each of these is established by existing and accepted standards.

1. Central visual acuity. The ability to recognize letters or characters which subtend an angle of 5 minutes, each unit part of which subtends a 1 minute angle at the distance viewed is accepted as standard. Therefore a 20/20 Snellen or A.M.A. and a 14/14 A.M.A. are employed as the maximum acuity of central vision, or 100% acuity for distance vision and near vision respectively.

2. Field vision. A visual field having an area which extends from the point of fixation outward 65, down and out 65, down 55, down and in 45, inward 45, in and up 45, upward 45, and up and out 55 is accepted as 100% industrial visual field efficiency.

3. Binocular vision. Maximum binocular vision is present if there is absence of diplopia in all parts of the field of binocular fixation, and if the 2 eyes give useful binocular vision.

(b) Minimum limits. The minimum limit, or the 0% of the coordinate functions of vision, is established at that degree of deficiency which reduces vision to a state of industrial uselessness.

1. Central visual acuity. The minimum limit of this function is established as the loss of light perception, light perception being qualitative vision. The practical minimum limit of quantitative visual acuity is established as the ability to distinguish form. Experience, experiment and authoritative opinion show that for distance vision 20/200 Snellen or A.M.A. Chart is 80% loss of visual efficiency, 20/380 is 96% loss, and 20/800 is 99.9% loss, and that for near vision 14/141 A.M.A. Reading Card is 80% loss of visual efficiency, 14/266 is 96% loss, and 14/560 is 99.9% loss. Table 1 shows the percentage loss of visual efficiency corresponding to the Snellen and other notations for distant and for near vision, for the measurable range of quantitative visual acuity.

2. Field vision. The minimum limit for this function is established as a concentric central contraction of the visual field to 5. This degree of contraction of the visual field of an eye reduces the visual efficiency to zero.

3. Binocular vision. The minimum limit is established by the presence of diplopia in all parts of the motor field, or by lack of useful binocular vision. This condition constitutes 50% motor field efficiency.

(c) Where distance vision is less than 20/200 and the A.M.A. Chart is used, readings will be at 10 feet. The percentage of efficiency and loss may be obtained from this table by comparison with corresponding readings on the basis of 20 feet, interpolating between readings if necessary. In view of the lack of uniform standards among the various near vision charts, readings for near vision, within the range of vision covered thereby, are to be according to the American Medical Association Rating Reading Card of 1932.

(2) MEASUREMENT OF COORDINATE FACTORS OF VISION AND THE COMPUTATION OF THEIR PARTIAL LOSS.

(a) Central visual acuity.

1. Central visual acuity shall be measured both for distance and for near, each eye being measured separately, both with and without correction. Where the purpose of the computation is to determine loss of vision resulting from injury, if correction is needed for a presbyopia due to age or for some other condition clearly not due to the injury (see section on miscellaneous regulations), the central visual acuity "without correction", as the term is used herein, shall be measured with a correction applied for such presbyopia or other preexisting condition but without correction for any condition which may have resulted from the injury. The central visual acuity "with correction" shall be measured with correction applied for all conditions present.

2. The percentage of central visual acuity efficiency of the eye for distance vision shall be based on the best percentage of central visual acuity between the percentage of central visual acuity with and without correction. However, in no case shall such subtraction for glasses be taken at more than 25%, or less than 5%, of total central visual acuity efficiency. If a subtraction of 5%, however, reduces the percentage of central visual acuity efficiency below that obtainable without correction, the percentage obtainable without correction shall be adopted unless correction is nevertheless necessary to prevent eye strain or for other reasons.

TABLE 1

Percentage of Central Visual Efficiency Corresponding to Specified Readings for Distant and for Near Vision for Measurable Range of Quantitative Visual Acuity

A.M.A. Test Chart or Snellen Reading for Distance	A.M.A. Card Reading for Near	Percentage of Visual Efficiency	Percentage Loss of Vision	A.M.A. Test Chart or Snellen Reading for Distance	A.M.A. Card Reading for Near	Percentage of Visual Efficiency	Percentage Loss of Vision
20/20	14/14	100.0	0.0	20/122.5	_____	40.0	60.0
20/15	14/17.5	95.7	4.3	20/137.3	_____	35.0	65.0
20/25.7	_____	95.0	5.0	20/140	14/98	34.2	65.8
20/30	14/21	91.5	8.5	20/155	_____	30.0	70.0
20/32.1	_____	90.0	10.0	20/160	14/112	28.6	71.4
20/35	14/24.5	87.5	12.5	20/175	_____	25.0	75.0
20/38.4	_____	85.0	15.0	20/180	14/126	23.9	76.1
20/40	14/28	83.6	16.4	20/200	14/141	20.0	80.0
20/44.9	14/31.5	80.0	20.0	20/220	14/154	16.7	83.3
20/50	14/35	76.5	23.5	20/240	14/168	14.0	86.0
20/52.1	_____	75.0	25.0	_____	14/178	12.3	87.7
20/60	14/42	69.9	30.1	20/260	14/182	11.7	88.3
20/60.2	_____	70.0	30.0	20/280	14/196	9.7	90.3
20/68.2	_____	65.0	35.0	20/300	14/210	8.2	91.8
20/70	14/49	64.0	36.0	20/320	14/224	6.8	93.2
20/77.5	_____	60.0	40.0	20/340	14/238	5.7	94.3
20/80	14/56	58.5	41.5	20/360	14/252	4.8	95.2
20/86.8	_____	55.0	45.0	20/380	14/266	4.0	96.0
20/90	14/63	53.4	46.6	20/400	14/280	3.3	96.7
20/97.5	_____	50.0	50.0	20/450	14/315	2.1	97.9
20/100	14/70	48.9	51.1	20/500	14/350	1.4	98.6
20/109.4	_____	45.0	55.0	20/600	14/420	0.6	99.4
20/120	14/84	40.9	59.1	20/700	14/490	0.3	99.7
_____	14/89	38.4	61.6	20/800	14/560	0.1	99.9

3. The percentage of central visual acuity efficiency of the eye for near vision shall be based on a similar computation from the near vision readings, with and without correction.

4. The percentage of central visual acuity efficiency of the eye in question shall be the result of the weighted values assigned to these 2 percentages for distance and for near. A onefold value is assigned to distance vision and a twofold value to near vision. Thus, if the central visual efficiency for distance is 70% and that for near is 40%, the percentage of central visual efficiency for the eye in question would be:

See Image

5. The Snellen test letters or characters as published by the Committee on Compensation for Eye Injuries of the American Medical Association and designated "Industrial Vision Test Charts" subtend a 5 minute angle, and their component parts a 1 minute angle. These test letters or the equivalent are to be used at an examining distance of 20 feet for distant vision (except as otherwise noted on the Chart where vision is very poor), and of 14 inches for near vision, from the patient. The illumination is to be not less than three foot candles, nor more than ten foot candles on the surface of the chart.

6. Table 1 shows the percentage of central visual acuity efficiency and the percentage loss of such efficiency, both for distance and for near, for partial loss between 100% and zero vision for either eye.

(b) Field vision.

1. The extent of the field of vision shall be determined by the use of the usual perimetric test methods, a white target being employed which subtends a 1 degree angle under illumination of not less than 3 foot candles, and the result plotted on the industrial visual field chart. The readings should be taken, if possible, without restriction to the field covered by the correction worn.

2. The amount of radial contraction in the 8 principal meridians shall be determined. The sum of the degrees of field vision remaining on these meridians,divided by 420 (the sum of the 8 principal radii of the industrial visual field) will give the visual field efficiency of one eye in per cent, subject to the proviso stated in the section on "Minimum Limits" that a concentric central contraction of the field to a diameter of 5 degrees reduces the visual efficiency to zero.

3. Where the impairment of field is irregular and not fairly disclosed by the 8 radii, the impaired area should be sketched upon the diagram on the report blank, and the computation be based on a greater number of radii, or otherwise, as may be necessary to a fair determination.

(c) Binocular vision.

1. Binocular vision shall be measured in all parts of the motor field, recognized methods being used for testing. It shall be measured with any useful correction applied.

2. Diplopia may involve the field of binocular fixation entirely or partially. When diplopia is present, this shall be plotted on the industrial motor field chart. This chart is divided into 20 rectangles, 4 by 5 degrees in size. The partial loss due to diplopia is that proportional area which shows diplopia as indicated on the plotted chart compared with the entire motor field area.

3. When diplopia involves the entire motor field, causing an irremediable diplopia, or when there is absence of useful binocular vision due to lack of accommodation or other reason, the loss of coordinate visual efficiency is equal to 50% loss of the vision existing in one eye (ordinarily the injured, or the more seriously injured, eye); and when the diplopia is partial, the loss in visual efficiency shall be proportional and based on the efficiency factor value of one eye as stated in table 2. When useful correction is applied to relieve diplopia, 5% of total motor field efficiency of one eye shall be deducted from the percent of such efficiency obtainable with the correction. A correction which does not improve motor field efficiency by at least 5% of total will not ordinarily be considered useful.

(3) INDUSTRIAL VISUAL EFFICIENCY OF ONE EYE. The industrial visual efficiency of one eye is determined by obtaining the product of the computed coordinate efficiency values of central visual acuity, of field of vision, and of binocular vision. Thus, if central visual acuity efficiency is 50%, visual field efficiency is 80% and the binocular vision efficiency is 100%, the resultant visual efficiency of the eye will be 50 x 80 x 100 = 40%. Should useful binocular vision be absent in all of the motor field so that binocular efficiency is reduced to 50%, the visual efficiency would be 50 x 80 x 50 = 20%.

(4) COMPUTATION OF COMPENSATION FOR IMPAIRMENT OF VISION. When the percentage of industrial visual efficiency of each eye has been thus determined, it is subtracted from 100%. The difference represents the percentage impairment of each eye for industrial use. These percentages are applied directly to the specific schedules of the Worker's Compensation Act.

(5) TYPES OF OCULAR INJURY NOT INCLUDED IN THE DISTURBANCE OF COORDINATE FACTORS. Certain types of ocular disturbance are not included in the foregoing computations and these may result in disabilities, the value of which cannot be computed by any scale as yet scientifically possible of deduction. Such are disturbances of accommodation not previously provided for in these rules, of color vision, of adaptation to light and dark, metamorphopsia, entropion, ectropion, lagophthalmos, epiphora, and muscle disturbances not included under diplopia. For such disabilities additional compensation shall be awarded, but in no case shall such additional award make the total compensation for loss in industrial visual efficiency greater than that provided by law for total permanent disability.

TABLE 2

Loss in Binocular Vision

No loss	equals	100.0%	Motor	Field	Efficiency
1/20	99.0
2/20	97.7
3/20	96.3
4/20	95.0
5/20	93.7
6/20	92.3
7/20	90.7
8/20	89.0
9/20	87.3
10/20	85.7
11/20	83.7
12/20	81.7
13/20	79.7
14/20	77.3
15/20	75.0
16/20	72.7
17/20	69.7
18/20	66.0
19/20	61.0
20/20	50.0

(6) MISCELLANEOUS RULES.

(a) Compensation shall not be computed until all adequate and reasonable operations and treatment known to medical science have been attempted to correct the defect. Further, before there shall be made the final examination on which compensation is to be computed, at least 3 months shall have elapsed after the last trace of visible inflammation has disappeared, except in cases of disturbance of extrinsic ocular muscles, optic nerve atrophy, injury of the retina, sympathetic ophthalmia, and traumatic cataract; in such cases, at least 12 months and preferably not more than 16 months shall intervene before the examination shall be made on which final compensation is to be computed. In case the injury is one which may cause cataract, optic atrophy, disturbance of the retina, or other conditions, which may further impair vision after the time of the final examination, note thereof should be made by the examining physician on his report.

(b) In cases of additional loss in visual efficiency, when it is known that there was present a preexisting subnormal vision, compensation shall be based on the loss incurred as a result of eye injury or occupational condition specifically responsible for the additional loss. In case there exists no record or no adequate and positive evidence of preexisting subnormal vision, it shall be assumed that the visual efficiency prior to any injury was 100%. In order to effect the above purpose, the examining physician should carefully distinguish, in regard to each of the coordinate factors, between impairments resulting from the injury and impairments not so resulting as established by the type of proof here stated. Such other impairments should, however, be also reported, separately. Computation must occasionally also be made of impairment of vision not resulting from the injury, as, for instance, for the purpose of computing additional indemnity due under the provisions of the Worker's Compensation Act on account of preexisting disability of one or both eyes.

Note: Example of computation covering partial disability to a single eye

A. Central Visual Acuity:

See Image

Note: Example of computation covering partial disability to both eyes

1. Left Eye is 62.3% efficient, see Example I.

2. Right Eye:

See Image

Note: Example of compensation covering enucleation of one eye and partial disability of the other eye

1. Left eye is 35.28% impaired (77.7% 83.3% = 64.72%; 100% - 64.72% = 35.28%, as allowance for binocular vision is inapplicable when the other eye is enucleated or blind), in indemnity payable for 88.2 weeks

2. Right eye is enucleated, which, results in indemnity payable for 275 weeks

3. Total payable: 88.2 weeks 3 (multiple injury) = 264.6 + 275 = 539.6 weeks The number of weeks indemnity indicated as payable for impairment of vision or for enucleation is in addition to indemnity for temporary disability . All results are subject to the limitation that the total amount of indemnity payable, including that for temporary disability, shall not exceed the indemnity which would be payable for permanent total disability . The statutory and legal rules applicable to the determination of additional compensation payable out of the special state fund on account of preexisting disabilities are not here stated

Notes

Wis. Admin. Code Department of Workforce Development DWD 80.26